PULMONARY EMBOLISM AFTER ABDOMINOPLASTY – ARE WE REALLY ABLE TO AVOID ALL COMPLICATIONS? CASE REPORTS AND LITERATURE REVIEW

INTRODUCTION

Venous thromboembolism (VTE) and pulmonary embolism (PE) is a serious and potentially lethal complication in plastic surgery patients. VTE is the second most common complication after discharge from the hospital, the second most common cause of extended stay in hospital and the third most common cause of both – excess mortality and financial costs¹. In the United Kingdom it is estimated that about 25,000 deaths each year are caused by hospital acquired thrombosis²; in the United States the estimation is about 100,000–200,000 deaths annually^3,4. It was also reported that about 18,000 cases of VTE are reported in plastic surgery patients in the United States each year⁵. Ten per cent of patients die within the first hour after clinical manifestation of PE, survivors can be stigmatized by right ventricular dysfunction and even failure⁶; 40%–80% of patients with VTE develop a post-thrombotic syndrome between 5–10 years after VTE that is associated with worsened quality of life predominantly due to chronic venous ulcerations⁷.

The study from 2007 reported that 40% from 596 ASPS surgeons have experienced DVT and 34% have diagnosed PE during their practice. Those numbers are surprisingly and alarmingly high. Seven per cent reported at least 1 patient death due to a postoperative PE⁸. Systematic review of literature found that among the body contouring plastic surgery cases the most risky procedure with regards to VTE is circumferential body lift (3.40%), followed by abdominoplasty combined with an intraabdominal procedure (2.17%), then abdominoplasty with concomitant plastic surgery (0.79%) and finally abdominoplasty alone (0.35%)⁹.

Venous thromboembolism starts most often intraoperatively with usually small nidus that can grow over the next couple of days and then propagate. It usually happens under appropriate conditions as a coincidence of risks factors and continuous limited mobility. The use of chemoprophylaxis, mechanical prophylaxis and early and active mobilization with other regimen precautions should minimize the risk of VTE and PE¹⁰.

Based on the aforementioned facts, there was a special guideline for prevention of VTE and PE elaborated and introduced into practice from 2012 at the Department of plastic surgery, Hospital Na Bulovce in Prague. This guideline adopted the risk scale list from acknowledged standards for prevention and treatment of VTE and PE recommended for use in general surgery in the Czech Republic¹¹. The risk of VTE is evaluated in every patient admitted to the hospital and appropriate preventive measures are taken. These measures include regimen precautions (early mobilisation, hydration, rehabilitation, smoking prohibition, cessation or elimination of risk hormonal therapy if possible), mechanical prevention (lower leg bandage or elastic socks, sequential compressive system) and chemoprophylaxis (enoxaparine, nadroparine or bemiparine). Despite the aforementioned precautions we have experienced two unexpected cases of pulmonary embolism in young patients with minimal risk ratio that we would like to present in the following case reports.

CASE REPORTS

Case Report 1

Nineteen-year-old female healthy patient was admitted for abdominoplasty with liposuction. No hormonal contraception or other medication was ascertained, BMI was 25. According to the scale only 1 point of risk was accounted and only regimen and mechanical prevention was recommended. However, the operating surgeon considered abdominoplasty with liposuction as an independent risk factor therefore also enoxaparine 0.2 ml per day was used, starting the evening before surgery. Liposuction 1000 ml of pure fat was performed followed by standard abdominoplasty with muscle tightening. 500 g of tissue was removed and surgery took 2 hours and 5 minutes. Postoperative period was uneventful; the patient was fully mobilized first day postoperatively and discharged on day 5 after surgery. Pulmonary embolism occurred 7 days after discharge and 12 days after the surgery. Embolism was demonstrated by CT angiography, with 2 cm diameter obstruction of the right main pulmonary artery and right bronchopneumonia, D-dimers were slightly elevated. PE was successfully treated, no heart impairment was confirmed using repeated echocardiography, however the patient has been complaining of mild dyspnoea after physical exercising. Complete haematological examination including molecular-genetic tests, Factor V Leiden, Factor II Prothrombin, Glycoprotein IV, Prothrombin activator inhibitor etc. was done with no pathology or gene mutation. The patient is currently treated with rivaroxaban (Xarelto, Bayer Pharma AG, Berlin, Germany).

Case Report 2

A 37-year-old female patient was admitted to hospital for abdominoplasty with wide diastasis of approx. 10 cm and small umbilical hernia. Hormonal contraception (Provera) was in use; the patient had a substitution therapy after thyreoidectomy. BMI of this patient was 26. One risk point was found and adequate measures were taken - regimen precautions and elastic stockings. Abdominoplasty with T scar was performed with muscle tightening and umbilical hernia repair; the surgery took 2 hours. No complications were noted in the postoperative period; the patient was again fully mobilized on day one after the surgery and discharged on day 3. Pulmonary embolism occurred 9 days after discharge and 12 days after the surgery. Embolism was demonstrated by CT angiography (embolization to the artery for pulmonary segment S7, S8, S10 on the right side, pulmonary infarction on the right side and bilateral pleuropneumonia). D-dimers were significantly elevated. Embolization was successfully treated. Again, no pathology or mutation was found in complete haematological survey. The patient stays under warfarinum natricum therapy (Warfarin Orion, Orion Corporation, Espoo, Finland) and still reports overall weakness and breathing discomfort.

DISCUSSION

VTE and PE have been reported after simple abdominoplasty in 0.35%, and in abdominoplasty with simultaneous plastic surgery in 0.79%⁹. The increased risk of VTE when liposuction is added to excision body contouring surgery was reported but did not reach statistical significance^12,13. More current review reports VTE in simple abdominoplasty without chemoprophylaxis between 0.04%–20% while incidence is 0%¹⁴ when chemoprophylaxis is used. In 2012 Raulo reported the results from a survey of 110,000 interventions from 440 surgeons. DVT in abdominoplasty occurred in 0.9%¹⁵. Abdominoplasty is definitely reported to be the plastic surgery procedure most often associated with DVT ant PE. Association of VTE or PE with abdominoplasty may be related to the interference with venous drainage from the legs and pelvis. Superficial venous network can be affected directly by the surgery; deep venous flow can suffer from increased intra-abdominal pressure after muscle tightening and indirectly by using special compressive garment¹⁶. Prolonged general anaesthesia with decline in peripheral resistance and limited ability of postoperative mobilisation can be an important additive factors too¹².

The risk factors for DVT and PE in general surgery and orthopaedic patients were identified during the last decades and scoring system to evaluate the individual patient risk was introduced to clinical practice. This scoring system does not only assess the risk of DVT and PE, but also, according to the relevant risk, offers an optimal management to prevent this event. In 1998, the board of directors of the American Society of Plastic Surgeons initiated the task force on deep vein thrombosis. It based its recommendations on guidelines published by the American College of Chest Physicians. However, the data reviewed did not include plastic surgery procedures and patients¹⁷. Therefore most plastic and aesthetic surgeons adopted the recommendations and standards from general surgery. In 2009, Venturi et al published their guidelines and recommendations for prevention of venous trombembolism in plastic surgery patients. They ascertained and modified the American College of Chest Physicians guidelines from 2008¹⁸. However, a considerable effort to overcome the lack of valid guidelines for plastic surgery can be clearly seen in the last years. In 2008, the Plastic Surgery Foundation (PSF) Research Oversight Committee identified the DVT risk stratification and prevention as a top patient safety research priority in plastic surgery specialty. The Venous Thromboembolism Prevention Study (VTEPS) was set up by PSF and at the same year it was demonstrated that post-operative inpatient enoxaparine reduces 60-day rates of symptomatic VTE without changing rates of hematoma¹⁹. In July 2011 the American Society of Plastic Surgeons Executive Committee approved the Venous Thromboembolism Task Force Report. Task Force members agreed that there was not enough evidence to make all-inclusive recommendations for plastic surgery prophylaxis medication, dosage or length of prophylaxis. The Task Force however released its full report: the 2005 Caprini Scale accompanied by the Task Force recommendations, patient venous thromboembolism risk self-assessor form and patient hand-out on venous thromboembolism signs and symptoms.

The risk of post-operative haematoma and bleeding are the main concerns expressed by plastic surgeons who do not use chemoprophylaxis²⁰. This particular complication, while using LMWH, was reported in some studies^12,21,22. Dini et al released the results of a prospective cohort study about safety of thromboprophylaxis in abdominoplasty that had to be suspended due to a high incidence of large haematomas and even wound dehiscence. However, they used rivaroxaban that is not primarily intended for general perioperative thromboprophylaxis and was approved by FDA for this purpose only for total hip and knee replacement surgery²³. On the contrary, no higher risk of postoperative haematoma when using chemoprophylaxis was reported by several other studies^19,20,24. The most important concern to consider is that PE is a potentially lethal complication and we should tolerate some higher risk of bleeding than the risk of massive PE¹⁰. At the Department of Plastic Surgery Hospital na Bulovce we adopted and strictly follow standards recommended for general surgery in the Czech Republic¹⁰ in accordance with the recommendations of the Czech Society for Haemostasis and Thrombosis.

The most common form of VTE is deep venous thrombosis (DVT) and the typical signs include oedema - often asymmetric, leg pain and tenderness, sensation of tension in the calf, change of skin colour, slightly increased temperature. Pulmonary embolism clinically presents by increased temperature, tachycardia, drop of blood pressure, chest pain, difficulty breathing and cough⁵. It is however accepted that only 33% of DVT cases present with symptoms²⁵ and most of them are silent without any discomfort. In both our patients the main clinical sign of pulmonary embolism was atypical intensive back pain and overall weakness that might have postponed slightly the correct diagnosis in the first case. However, in the second case that followed shortly after the first one, this diagnosis was considered first.

The risk of DVT and PE is the highest at the time of limited mobilisation during surgery or close to it. After complete mobilisation of the patient the risk become steadily lower. It was however reported that venous thromboembolism risk may remain elevated for up to 90 days after a surgery. According to a study done on 947,454 middle aged women in the United Kingdom, women were 70 times more likely to be admitted for venous thromboembolism in the first six weeks after an inpatient operation and 10 times more likely after a one-day surgery compared with those not having surgery. The risk was lower but still substantially increased 7–12 weeks after the surgery. This pattern of risk was similar for pulmonary embolism and deep venous thrombosis²⁶. Yale et al developed a model to determine the risk of DVT in the post-hospitalization period. Univariate and multivariate logistic regression analyses were used to identify risk variables related to DVT. Within 60 days after discharge from a hospital was DVT the reason of a new admission to hospital in 93.2% in high risk patients, 52.9% in moderate risk patients and 12.0% in low risk patients²⁷. In both our cases the risk score according to the risk assessment questionnaire was 1. We are aware of the role of immobilisation and prolonged risky period for DVT and PE. Both our patients were fully mobilized and have had rehabilitation focusing on self-care and breathing after abdominoplasty from the first day after the surgery. The risk of PE decreases at the time after surgery and was less expected, especially in low risk patients. PE occurred in both our patients 12 days after the surgery, 11 days after full mobilisation and 7 or 9 days after discharge to home care. The length of stay in hospital greater or equal to 4 days was recognized as an independent risk factor for DVT²⁸. This may be an additive risk factor for our first patient who was discharged on the 5^th post-operative day.

The age of the patients was shown to be an additive risk factor in the development of DVT and PE. Patients over 40 years old are in greater risk of both complications compared with younger patients with risk approximately doubling in every decade^29,30. Both our patients were younger than 40 years (19 and 37 years).

The duration of chemoprophylaxis has been discussed, however it is recommended that prophylaxis to be continued only until the patient with low and moderate risk is discharged from the hospital. In high-risk patients, the chemoprophylaxis should be prolonged for 7–10 days. Prolonged chemoprophylaxis is – according to our standard – used in patients with a risk score equal or more than 6. Our patients were at low risk and prophylactic measures were discontinued at the day of discharge from the hospital.

Education of patients about the signs of DVT is very important for their cooperation and acceptance of preventative measures and also to recognise early signs of this complication. Sadideen et al reported that after introduction of the special questionnaire there was a dramatically significant improvement in the awareness of DVT (90% vs. 49%; P<0.01), its signs (80% vs. 50%; P<0.01) and preventive measures (84% vs. 39%; P<0.01) among the patients³¹. At our department each patient is educated about the DVT and PE at the time of admission to the hospital.

CONCLUSION

The thromboembolic disease and pulmonary embolism is a potentially lethal complication of all surgeries, including reconstructive and aesthetic plastic surgical procedures. There are, however, prophylactic measures established to prevent this dangerous event. These are regimen precautions, mechanical support of blood flow and chemoprophylaxis. These measures can be employed separately or in combination, especially in high-risk patients. International or national standards for prevention of the DVT and PE should be strictly implemented to everyday practice at all surgical departments. But even then there is a possibility of this complication and sometimes in the most unlikely patients. It is our responsibility therefore to be aware of this complication and to consider seriously all, even atypical, signs of this complication.

Declaration of interest: The authors have no financial interest to declare in relation to the content of this article, in any of the products, devices or drugs mentioned in the article.

Corresponding author:

Martin Molitor, M.D., PhD.

Department of Plastic Surgery

Hospital Na Bulovce and First Faculty of Medicine, Charles University, Budínova 2, Prague 8, 181 10

Czech Republic

E-mail: martinmolitor1@gmail.com